feat: upgrade to Angular v22

[timdeschryver]

This PR updates the lib to v22.
AFAIK it should be a breaking change, however there is one change I'm not sure on how to handle it. The registration of provideHttpClient now defaults to fetch, instead of XMLHttpRequest.

What it does:

• update versions
• update to the ESLint flat config (the older version isn't compatible anymore within angular-eslint)
• update node version
• update tsconfig (bringing it up to date for the next update)

What not:

• update the examples to follow the new default of standalone applications, instead it makes sure it works as before (hence the many file changes)
• update to Vitest (karma/jasmine is deprecated)

I think the "what not" could be separate issues to keep it aligned with Angular's future.